Paraffin scraper



Dec. 27, 1955 J. s. TAYLOR PARAFFIN SCRAPER 2 Sheets-Sheet l IN V EN TOR.

A 7' TORNEY Filed March 29, 1954 Unite States Patent O 2,728,398 PARAFFIN SCRAPER .lulian S. Taylor, Milwaukee, Wis. Application March 29, 1954, Serial No. 419,278 3 Claims. (Cl. 166-170) The present invention relates generally to oil wells and more particularly to a device for cleaning the bore of the tubing of parafiin in a flowng oil well.

In the operation of oil wells, it has been found that paraflin and other asphaltic or bituminous compounds tend to collect on the walls of the bore of the tubing within the well. This accumulation builds up gradually until it seriously restricts the flow of the well and sometimes entirely clogs it. When either happens it is necessary to pull the tubing from the well and clean it of the accumulations of 'paraffin by steaming or some other suitable manner. This operation takes considerable time and is expensive and production from the well is delayed until the tubing is in place again.

The present invention is designed to overcome this difficulty by providing a device that is continuously operated by the pressure of the well and which carres scrapers that contact the bore of the tubing and dislodge the paraffin as it accumulates and allows it to flow out of the well with the oil.

The principal object of the present invention is to provide a device for removing paraflin from the bore of an oil well tubing which is continuously operated by the gas and fluid pressure flow from the well.

Another object is to provide a device of the class described which employs an expandable and contractible packing element provided with scrapers thereon and which when expanded utilizes the thrust of the well flow to raise the device to the top of the well where the packing element is automatically released to contract in size to allow the by-pass of well fluid therearound, and the device returns to the well bottom by the action of gravity.

A further object is to provide a device of the class described that is comparatively cheap to manufacture and requires little or no attetion after being placed in operation.

Yet another object is -to provide a device for dislodging paraflin from the bore of a flowing well tubing and that will not restrict the flow of fluid from the well.

Other objects will be apparent from the following description when taken in conjunction with the accompanying two sheets of drawings, wherein:

Figure 1 is a fragmentary vertical sectional view of a well tubing showing the device therein;

Figure 2 is a vertical sectional view taken substantially along line 2-2 of Fig. l;

Figure 3 is a vertical sectional view similar to Fig. 2, but showing the device in another position;

Figure 4 is an enlarged fragmentary vertical sectional View showing the attachment of the scraper to the linkage; and,

Figure 5 is a transverse sectional view through one of the scrapers.

Like characters of reference designate like parts in those figures of the drawings in which they occur.

In the drawings:

Reference numeral 1 indicates the device as a whole, being elongate cylindrcally in general configuration, vertically disposed within a well tubing 2. The device 1 has an elongate upper body 5 and an elongate lower body 6 of substantially equal diameters. The upper body 5 is centrally through bored to slidably receive an elongate latch rod 7 within its upper end portion. The latch rod 7 is held in place within the body 5 by a disc 8 integrally connected transversely to the rod 7 at a selected point ICC spaced from its upper end and slidably disposed within an enlarged bore 9 adjacent the upper end of the body 5. The bore 9 is closed by a threaded plug 10, which limits the upward movement of the disc 8. The rod 7 projects upwardly above the plug 10 a distance substantially equal to the length of slidable movement of the disc 8 within the bore 9. A disc 11 similar to the disc 8, is rgidly attached to the top end of the rod for the purposes more fully explained hereinbelow. The body 5 has an enlarged bore 12 extending upwardly from its lower end 13 a selected distance, forming a comparatively thin-walled section 14, which is closed at its lower end by the threaded plug 15.

The upper portion of the lower body 6 is exteriorly reduced in diameter, as by a lathe, forming an elongate integral upstandng rod 16. The rod 16 is axially disposed slidably within the plug 15 and is rigidly connected to a cylindrical disc 17 by a screw 18. The cylindrical disc 17 is vertically slidably disposed within the bore 12 above the plug 15. Adjacent the upper end of the bore 12, the wall 14 is vertically slotted to receive i a vertically disposed bell-crank latch 19 pivotally attached to the wall 14 by the transverse pin 20. The depending leg of the latch 19 has an inwardly projecting horizontal shoulder 21 spaced downwardly a distance great enough to allow the disc 17 to be seated thereabove (Fig. 3). The latch 19 has a downwardly and outwardly slanting inner edge 22, extending from the shoulder 21 to the edge of the wall 14. The purpose of this slanting edge 22 is to allow the disc 17 to forcibly urge the de- I pending leg of the latch 19 outwardly as diagrammatically shown by dotted lines (Fig. 3), as the disc 17 is moved upwardly within the bore 12 to allow the disc to be seated above the shoulder 21. A strap metal spring 23 is rigidly attached to the wall 14 by a screw 24 and extends upwardly over the lower end of the latch 19 and holds the latch 19 in exterior alignment with the body 5. The lower end of the latch-rod 7 extends downwardly into the upper end of the bore 12 and rests upon the upper end 25 of the latch 19.

Adjacent the lower end of the rod 16 s a horizontal circumferential shoulder 30 on the body 6. A cylindrical member 31, having upper and lower ends 32 and 33, respectively, is slidably disposed around the rod 16, between the plug '15 and the shoulder 30. The lower end 33 of the member 31 is plurally slotted radially to receive a like plurality of elongated narrow depending upper links 34 of substantially equal length, pivotally attached adjacent their upper ends within the Slots by pins 35. To the lower end of each link 34 is attached a like plurality of lower links 36, by a pivot pin 37. The shoulder 30 is plurally slotted radially similar to the end 33, to receive the lower ends of the links 36 on pivot pins 38. The pivot pins 35 and 38 are placed as close as practcable to the rod 16, and the pivot pin 37 is placed adjacent the outermost edges of the links 34 and 36, so` that when the links 34 and 36 are in longitudinal alignment, any downward movement of the member 31 will pivot the links 34 and 36 outwardly at the pivot pin 37 A hollow cylindrical packer 40, preferably of rubber or other suitable resilient material, is circumferentially disposed around the member 31 and the upper links 34. The upper end of the packer 40 is held in contiguous contact with the member 31 by a snap ring 41 over a suitable ci'cumferential groove in the member 31. The lower end of the packer is held in positive contact with the links 34, by a screw 42 (Fig. 4). Adjacent the lower end of the packer 40 and integral therewith, are a plurality of radially spaced staggered conical shaped scrapers 44. Each scraper 44 has a renforcing element 45 molded within itself (Fig. 5). The'packer 40 nor- 

1. A PARAFFIN CLEANER FOR FLOWING WELLS INCLUDING, AN ELONGATE CENTRALLY BORED UPPER BODY HAVING CLOSED UPPER AND LOWER ENDS; AN ELONGATE LOWER BODY HAVING AN UPSTANDING INTEGRALLY CONNECTED ROD ON ITS UPPER END, THE UPPER END OF SAID ROD LONGITUDINALLY DISPOSED WITHIN AND SLIDABLY CONNECTED TO THE LOWER END OF SAID UPPER BODY; A CYLINDRICAL MEMBER SLIDABLY DISPOSED ON SAID ROD; LINKAGE PIVOTALLY CONNECTED INTERMEDIATE ITS ENDS AND CONNECTING SAID MEMBER WITH THE UPPER END OF SAID LOWER BODY, SAID LINKAGE PIVOTING OUTWARDLY RELATIVE TO SAID ROD UPON DOWNWARD MOVEMENT OF SAID MEMBER; RESILIENT PACKING ENCIRCLING AND CARRIED BY SAID CYLINDRICAL MEMBER AND THE UPPER ENDS OF SAID LINKAGE, SAID LINKAGE RADIALLY EXPANDING THE LOWER END OF SAID PACKING UPON DOWNWARD MOVEMEMT OF SAID OF SAID CYLINDRICAL MEMBER TO PARTITION A WELL PIPE IN WHICH IT IS POSITIONED TO RECEIVE THRUST FROM THE WELL FLOW TO RAISE SAID BODIES; SCRAPERS CARRIED BY AND INTEGRAL WITH THE LOWER END OF SAID PACKING; A LATCH PIVOTALLY CARRIED BY THE WALL OF SAID UPPER BODY FOR HOLDING SAID ROD AND SAID LOWER BODY IN RAISED RELATION WITH SAID UPPER BODY UPON CONTACT OF THE LOWER END OF SAID LOWER BODY WITH THE WELL BOTTOM; A LATCH-ROD IN CONTACT WITH SAID LATCH AND SLIDABLY CARRIED AXIALLY BY THE UPPER END OF SAID BODY AND PROJECTING UPWARDLY THEREABOVE FOR RELEASING SAID ROD UPON CONTACT OF THE UPPER END OF SAID LATCH-ROD WITH THE WELL HEAD; AND A HELICAL SPRING AXIALLY DISPOSED AROUND SAID ROD BETWEEN THE LOWER END OF SAID UPPER BODY AND THE UPPER END OF SAID CYLINDRICAL MEMBER URGING SAID CYLINDRICAL MEMBER IN A DOWNWARD DIRECTION WHEN SAID ROD IS IN LATCHED POSITION AND FOR FORCING SAID BODIES APART WHEN SAID ROD IS IN AN UNLATCHED POSITION THEREBY ALLOWING CONTRACTION OF SAID PACKER FOR PERMITTING THE FLOW OF WELL FLUID THEREAROUND AND THE FREE FALL OF THE CLEANER BY GRAVITY TOWARDS THE WELL BOTTOM. 